阅读说明：本技术 一种垃圾焚烧高效低成本的综合炉内脱硝方法 (Efficient and low-cost comprehensive in-furnace denitration method for waste incineration ) 是由 王惠生 于 2019-09-11 设计创作，主要内容包括：本发明涉及垃圾焚烧处理的技术领域,具体来说,是一种垃圾焚烧高效低成本的综合炉内脱硝方法。本发明的方法在二燃室内进行低氮燃烧步骤,同时结合尿素雾化进行脱硝处理,处理合格的烟气排出二燃室进行后续处理；通过低氮燃烧的工艺、尿素雾化脱硝、高效脱硝二燃室进行综合的脱硝方法,成本低,效果好。(The invention relates to the technical field of waste incineration treatment, in particular to a waste incineration efficient and low-cost denitration method in a comprehensive furnace. In the method, the low-nitrogen combustion step is carried out in the secondary combustion chamber, the denitration treatment is carried out by combining with urea atomization, and qualified flue gas is discharged out of the secondary combustion chamber for subsequent treatment; the comprehensive denitration method is carried out by a low-nitrogen combustion process, a urea atomization denitration and high-efficiency denitration secondary combustion chamber, and is low in cost and good in effect.)

1. a high-efficiency low-cost comprehensive in-furnace denitration method for waste incineration comprises the following specific steps: carrying out low-nitrogen combustion in the secondary combustion chamber, carrying out denitration treatment by combining with urea atomization, and discharging qualified flue gas out of the secondary combustion chamber for subsequent treatment;

specifically, flue gas enters a secondary combustion chamber from a flue gas inlet, low-nitrogen combustion is mainly performed in a shell of the secondary combustion chamber, the flue gas rotates from top to bottom, and then the flue gas is discharged out of the secondary combustion chamber from a flue gas outlet;

the temperature of the secondary chamber is controlled to be 850-950 ℃;

the low-nitrogen combustion in the second combustion chamber shell is provided with sectional air supply, and the air quantity of each section is controllable;

And (4) introducing atomized urea at the top of the secondary combustion chamber to perform denitration treatment on the flue gas.

2. The method for denitration in a waste incineration comprehensive furnace with high efficiency and low cost according to claim 1, characterized in that the segmented air supply is three-segment air supply.

3. the method for high-efficiency and low-cost integrated denitration by waste incineration as set forth in claim 2, wherein the air supply positions are respectively arranged at 1/4, 2/4 and 3/4 in the height direction of the secondary combustion chamber from bottom to top.

4. The method for denitration in a comprehensive furnace by utilizing waste incineration with high efficiency and low cost as claimed in claim 2 or 3, characterized in that the direction of air supply is opposite to the running direction of flue gas in the secondary combustion chamber.

5. The method for high-efficiency and low-cost integrated denitration by waste incineration as claimed in claim 1, wherein the secondary combustion chamber is provided with air supply ports which are respectively located at 1/4, 2/4 and 3/4 in the height direction of the secondary combustion chamber from bottom to top.

6. The integrated denitration method in a garbage incineration furnace with high efficiency and low cost according to claim 5, characterized in that the inlet of the air supply port is opposite to the running direction of the flue gas in the secondary combustion chamber; an air quantity regulating valve is arranged on the air supply opening.

7. The method for denitration in a comprehensive furnace by utilizing waste incineration with high efficiency and low cost as claimed in claim 1, wherein the secondary combustion chamber is of a cylindrical structure, and the height-diameter ratio of the inner clear space is 4: 1.

8. The method for high-efficiency low-cost integrated denitration by waste incineration as claimed in claim 1, wherein the flue gas inlet and the flue gas outlet of the secondary combustion chamber are both tangentially arranged.

9. The method for denitration in a waste incineration comprehensive furnace with high efficiency and low cost according to claim 1, characterized in that a urea atomizer is arranged at the top of the secondary combustion chamber, and the working diameter of the urea atomizer corresponds to the diameter of the secondary combustion chamber.

10. The method for denitration in a waste incineration comprehensive furnace with high efficiency and low cost according to claim 1, characterized in that the number of the urea atomizing nozzles is 3-4, one urea atomizing nozzle is arranged at the central point of the middle of the second combustion chamber, and the rest urea atomizing nozzles are uniformly distributed on the plane above the path of the flue gas rotation.

Technical Field

The invention relates to the technical field of waste incineration treatment, in particular to a waste incineration efficient and low-cost denitration method in a comprehensive furnace.

Background

The waste incineration is a process of subjecting waste to oxidation at a high temperature by appropriate thermal decomposition, combustion, melting, or other reaction to reduce the volume of the waste to form a residue or a molten solid substance.

The waste incineration facility must be equipped with a flue gas treatment facility to prevent heavy metals, organic pollutants and the like from being discharged into the environment medium again. The heat generated by burning the garbage is recycled, and the purpose of recycling the waste can be achieved.

the conventional flue gas denitration and catalytic denitration (SCR) has high efficiency and high cost; the non-catalytic denitration (SNCR) has low removal efficiency and is difficult to reach the standard.

the method provides the in-furnace denitration comprehensive process and method which are applicable to waste incineration, high in efficiency, low in cost and free of catalysts.

disclosure of Invention

Aiming at the defects of high catalytic denitration efficiency, high cost and low removal efficiency in the prior art, the invention provides a waste incineration high-efficiency low-cost comprehensive in-furnace denitration method, and aims to solve the technical problems.

The technical scheme of the invention is as follows:

A high-efficiency low-cost comprehensive in-furnace denitration method for waste incineration comprises the following specific steps: carrying out low-nitrogen combustion in the secondary combustion chamber, carrying out denitration treatment by combining with urea atomization, and discharging qualified flue gas out of the secondary combustion chamber for subsequent treatment;

Specifically, flue gas enters a secondary combustion chamber from a flue gas inlet, low-nitrogen combustion is mainly performed in a shell of the secondary combustion chamber, the flue gas rotates from top to bottom, and then the flue gas is discharged out of the secondary combustion chamber from a flue gas outlet;

The temperature of the secondary chamber is controlled to be 850-950 ℃;

The low-nitrogen combustion in the second combustion chamber shell is provided with sectional air supply, and the air quantity of each section is controllable;

And (4) introducing atomized urea at the top of the secondary combustion chamber to perform denitration treatment on the flue gas.

Furthermore, the sectional air supply is three-section air supply; further preferably, the air supply positions are respectively arranged at 1/4, 2/4 and 3/4 in the height direction of the second combustion chamber from bottom to top; furthermore, the direction of the air supply is opposite to the running direction of the smoke in the secondary combustion chamber. The nitrogen in the air reacts to generate nitrogen oxide during combustion, and the invention can reduce the generation of nitrogen oxide by the design of the secondary combustion chamber and control the combustion, control the air supply and realize low-nitrogen combustion.

Further, an air supply port is arranged on the second combustion chamber, and the air supply port is respectively positioned at 1/4, 2/4 and 3/4 in the height direction of the second combustion chamber from bottom to top; the inlet of the air supply port is opposite to the running direction of the flue gas in the secondary combustion chamber; an air quantity regulating valve is arranged on the air supply opening. The air inlet positions are evenly distributed at intervals, so that the uniformity and the rationality of air supply are improved, and the three air supply ports and the flue gas inlet are evenly distributed together, so that the uniformity of air supply is further improved, and favorable conditions are provided for sufficient combustion.

Further, the second combustion chamber is of a cylindrical structure, and the height-diameter ratio of the inner clear space is 4: 1, the setting of this height-diameter ratio is corresponding with air feed mouth and flue gas import quantity, and the regional reasonable gas distribution of being convenient for more that forms improves the treatment effect.

The flue gas inlet and the flue gas outlet of the second combustion chamber are tangentially arranged.

the top of the second combustion chamber is provided with a urea atomizing nozzle, and the working diameter of the urea atomizing nozzle corresponds to the diameter of the second combustion chamber; preferably, the number of the urea atomizing nozzles is 3-4, one urea atomizing nozzle is arranged at the central point of the middle of the second combustion chamber, and the rest urea atomizing nozzles are uniformly distributed on the plane above the path of the rotating smoke. Through the reasonable setting of shower nozzle, improve and spray the effect, wholly increase treatment effect, the denitration is thorough.

The beneficial effect of the invention is that,

In the process, in the low-nitrogen combustion section, the air quantity is controllable, the oxygen supply on the upper part of the secondary combustion chamber is reduced to the maximum extent through segmented air supply, and under the condition of insufficient oxygen, the oxygen firstly reacts with carbon monoxide in the flue gas, so that the generation of nitrogen oxides is reduced.

in the process, a secondary combustion chamber specially designed for denitration, a cylindrical secondary combustion chamber and a rotary flue gas trend can be in full contact reaction with ammonia gas in the secondary combustion chamber; compared with the conventional and small-particle-size urea, the urea atomization greatly improves the denitration reaction speed and the mixing degree with the flue gas; the arrangement of 2-3 spray heads and 1 spray head in the middle on the flue gas rotating path is uniformly distributed at the top of the second combustion chamber, so that the atomized urea and the flue gas can be fully mixed and reacted.

In a word, the integrated in-furnace denitration method with high efficiency and low cost for waste incineration is an integrated denitration method by a low-nitrogen combustion process, a urea atomization denitration and high-efficiency denitration secondary combustion chamber, and has low cost and good effect.

Drawings

in order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

FIG. 1 is a schematic view of a flue gas treatment line according to the present invention;

FIG. 2 is a schematic structural view of a second combustion chamber in the present invention;

FIG. 3 is a schematic layout of the urea atomizer of FIG. 2.

Wherein, the device comprises a smoke inlet 1, a smoke outlet 2, an air supply port 3 and a urea atomizing nozzle 4.

Detailed Description

in order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.